Subspecific and Geographic Variation in Life-History Characteristics in Two Subspecies of Painted Turtle, Chrysemys Picta Bellii and Chrysemys Picta Dorsalis
Date of Graduation
Master of Science in Biology
Reproductive and body size characteristics were compared for two subspecies of Chrysemys picta to determine if variation in these traits is mainly influenced by geography (i.e. latitude and elevatoin) or if they vary subspecifically. Specimens of C. p. bellii and C. p. dorsalis were collected from the same latitude and elevation in southern Missouri. Male body sizes were not significantly different between the subspecies at the same latitude. Female body sizes, however, did differ significantly. Clutch sizes were significantly correlated to body size in both subspecies. However, the relationship between clutch size and body size differed between subspecies with C. p. bellii producing more eggs with increasing plastron length. Other contributing environmental factors may explain this result. Body size data were also analyzed from a population of C. p. bellii from Wisconsin and compared to that of the Missouri group. The results showed that the two groups differed significantly in female and male body size, with the more northern population having larger average sizes. Means of clutch sizes and body sizes for each group were also compared to predicted values generated by regression equations (Lindeman, P., 1997. J. Herp 31:155-161) based on latitude and elevation. This study provides evidence that these life history traits vary geographically rather than subspecifically in this species.
© Dana Jill Whitham
Whitham, Dana Jill, "Subspecific and Geographic Variation in Life-History Characteristics in Two Subspecies of Painted Turtle, Chrysemys Picta Bellii and Chrysemys Picta Dorsalis" (1999). MSU Graduate Theses. 121.